I don’t think LOTR is going away. They’d be pretty foolish to stop printing the existing content as it always seems to sell out as soon as it gets into stock. I was waiting over a year (maybe two?) to get the Dwarrowdelf packs and I finally managed to grab them in the most recent reprint a few weeks ago, and they’re mostly out of stock again. The saga expansions have similar issues.
What I do think will happen is they’re going to do something to get away from the current model. I don’t know what that means, maybe less frequent expansions more along the size of the deluxe or saga sets? Maybe they’ll take a lesson from Arkham and come up with more campaign type content. Hard to say for sure.
The only thing I can say is that looking at the cost of the content I haven’t purchased yet (which is most of it) is a little daunting. Getting new players into the game is going to get increasingly difficult for the same reason. I keep an eye out for people selling the game on BGG and I recently saw someone list their entire collection which was almost all the content released to date, for something like $1,100. That’s… a lot. But it’s still probably a discount over buying the stuff new.
I do think the L5R LCG is going to die some point soon. The game really looked and sounded interesting initially, and I think they had some good ideas, but when it released it was too complex and the games lasted too long. I say this as someone who never played it, but watched some matches, and I’ve heard that opinion echoed by others. They couldn’t stripped a few things away from it and sped up the game and it might have had a better chance.